boyfriends mother :/

okay so me and my boyfriend been together for 3 years and we started to try for a baby about a year ago when we got our own place but still no luck. and about 3 and a half months ago his mother moved in with us because she and his dad (her husband) split up..again for the third time.. so i decided to wait until she moves out since she got the extra room..anyways its been okay except now that his mom is living with us his siblings come over almost every weekend and it drives me crazy because they don't pick up after themselves and they eat EVERYTHING!!! (both adults in college) I'm not the one to be stingy when it comes to food but literally they open everything and eat for like 3 people I don't have money to buy groceries every week so it bothers me and after talking to my boyfriend about it we got into an argument and things escalated quickly so I decided to just drop it because im not the one to argue about stupid stuff. I'm the type of person that likes my space I don't mind company but not all the time he's the total opposite he doesn't mind his family being over all the time which causes a LOT of problems in the relationship anyways long story short we've decided that the relationship wasn't healthy anymore with all the arguing and end things. it hurts so much because he doesn't see that it all went downhill when his mom moved in and now we're ending things. let me remind you guys his mom has 2 jobs and still has nothing saved up..any advice? am I overreacting or doing the right thing?